The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In many rotating gear applications, a first order imbalance is detected and controlled by measuring a runout of the gear. For example, in driveline applications, the first order imbalance is controlled by measuring the combined axial and radial runout of the rear axle input flange. However, such standard measurement is not applicable to a gear assembly having a flangeless connection.
More particularly, in one example, runout is defined as the difference between the high and low measurement of a rotating shaft under a dial indicator. The runout measurement measures both circularity (i.e., form error) and concentricity (i.e., positional error). In a rotating gear assembly having a flangeless connection (e.g., a plug-in system), the form error of the mating parts is not critical because, when assembled, the male and female parts do not rotate relative to each other, such that errors in roundness may not affect system balance. In addition, it may be unnecessary to measure the runout of a non-round shaft since any deviation in circularity is directly translated to the part. For example, for a splined shaft or a shaft with a keyway, the measurement data would need to be filtered to inhibit the non-round areas from affecting the measurement or a round gauge surface is added to the part to represent the position of the actual functional surface. This is seen in instances where a shaft is measured above or below a splined area to establish runout.
Accordingly, the positional error between the shaft geometric centerline and the shaft axis of rotation becomes a key factor in determining imbalance. However, current measurement techniques measure the concentricity as part of circularity and thus, the runout is generally measured and then the concentricity is extracted from the runout. These and other issues are addressed by the teaching of the present disclosure.